/Engine/Source/Runtime/Engine/Public/MaterialShared.h
void FillUniformBuffer ( const [FMaterialRenderContext](API\Runtime\Engine\FMaterialRenderContext) & MaterialRenderContext, TConstArrayView< [IAllocatedVirtualTexture](API\Runtime\RenderCore\IAllocatedVirtualTexture) * > AllocatedVTs, const [FRHIUniformBufferLayout](API\Runtime\RHI\FRHIUniformBufferLayout) * UniformBufferLayout, uint8 * TempBuffer, int TempBufferSize ) const